Palm Beach Sculptra doctors

Sculptra lasts long time.

Specifically, it can last for up to two years and if it is enhanced at the one year mark, probably longer.
Some of the duration depends on how much product is put in, some depends on how much collagen the person makes and some depends on how many sessions are undertaken.

Since Sculptra works by creating new collagen, the collagen created tends to be very durable.

No, Sculptra is a liquid that will have some effect based on gravity but this is minimal and the particles injected along with the water will tend to stay where they are put. 

Since you would massage the Sculptra following injections, you will move it around to keep it evenly distributed. Sculptra is not going to drop and in general does a great job of adding volume to the areas where it is injected.

Other products including Juvederm are soft gels that stay where they are injected. In some areas, muscles may move the product a little. For instance, when you inject around the mouth, there are muscles that can move the product and in some patients that are very expressive, it can move a little because their face moves so much.

In the cases where the product moves, the results are usually not visible but if they are, there are ways to correct them.

I'd have to see you in order to answer your question specifically, but any number of fillers can be used to help with your problem.  Please make sure to see an experienced and qualified physician as this is considered an advanced use of fillers.